Brand new printer. Clogged extruder. Help :[
Hi All,
This is all pretty new to me, but got a brand new pre-assmbled in the mail last week. First prints turned out pretty good when doing the test prints on the SD card, anytime I ventured away from the default files ran into issues, which I blamed on my inexperience. I had ventured away from the included filament into an amazon 'color bundle' with decent reviews, but went back to eliminate it as a potential issue. So using included filament, went back to test prints, and I tried to print the triceratops and thats when my troubles began. Just an awful and odd print. Printed batman no problem. Then I printed, honestly don't know its name, but it was the dragon statue. Gets all the way up to the last few layers and just stopped. I wasn't watching it. Pretty discouraged left it off over night and tried to come back at it today. Went for the frog and nothing was coming out of the extruder.
Unloading filament option and pulling. Nothing. Just grinds the gears.
Tried heating print head up to 290 and using acupuncture got some materials off.
After acupuncture, I tried to pretend it was normal and start the frog. Some material came off on the first layer, I thought good the jam is cleared lets just pull the filament out and confirm. Still won't come out of the printer just grinds when I hit unload. I pulled softly at first, but i pulled so hard at one point the printer started to lift from the table (oops)
Any ideas?
RE: Brand new printer. Clogged extruder. Help :[
Hi Rachel,
I have had this happen myself. The filament is melting and being allowed to expand a bit beyond the nominal 1.75mm, and then a retraction (or just an unload) pulls the larger blob into the PTFE tube and it jams there. There are several ways this can happen:
1) The nozzle and heatbreak in the hotend are not tight against each other.
2) The PTFE tube has lifted a bit against the heatbreak
3) The Prusa-supplied heatbreak is a custom design with a wider part that is intended to help when the MMU2 option is used, but it can lead to this sort of jamming.
You are going to have to disassemble the hotend to fix this, and to do that you need to partially disassemble the extruder. Remove the fans, remove the two screws under the motor from the front, and the two topmost screws in the back that go into the motor. The front part of the extruder and the motor will pull off, and you can then pull out the hotend. It would probably be worth scanning through the E-axis assembly instructions for guidance. Note that screws are of different lengths, don't mix them up.
If you're lucky, when you pull out the PTFE tube (press down on the black collet before pulling on it), the jam will be entirely there and you may be able to pull it out from the other end. If not, Prusa should have supplied you with some spares (I know the kit version does). Note that one end of the tube, as Prusa supplies it, has a slight bevel to it. This end goes towards the nozzle. Make sure the tube is firmly pushed down all the way.
Follow the E3DV6 assembly instructions at https://e3d-online.dozuki.com/Guide/V6+Assembly/6?lang=en for reassembly. I highly recommend inserting a collet clip on the hotend collet, to prevent the tube from backing out. Since Prusa didn't supply one, you can print one (there are many examples on Thingiverse). In a pinch, cut a normal (not small) paper clip leaving just one U and bend that around the underside of the collet. Take care that it doesn't stick out much or you'll have trouble reassembling the extruder.
Pay close attention to the instructions for tightening the nozzle against the heatbreak.
You can't do too much about the custom heatbreak without replacing it with one that doesn't have the wider section. I have done this, but it should not be necessary.
When slicing files on your own, make sure the retraction setting is no more than 0.6mm to avoid similar problems. Let us know if this helps.
RE: Brand new printer. Clogged extruder. Help :[
Rather than the atomic "rip it all apart and start fresh" option, especially with a printer you did not assemble, easier to start with simple things.
Verify you have a Prusa - and which model.
Also, I'm not sure what state the filament is in. I presume you can unload the filament. That is, preheat to PLA, then use the UNLOAD from the LCD menu. If the extruder is clicking during unload, try increasing the idler door tension, and pulling lightly during the unload. Lifting the printer by the filament isn't needed.
If you can't unload the filament, verify the hot end is warming up: the LCD should show the temperature as 215/215 ... if you see 215/0, something odd is happening. And a different diagnostic path is needed.
fyi: There is nothing in the filament path where the filament can expand to a point it will not come out of the extruder. Largest diameter is 2.2 mm, and that will fit through the 2.0mm PTFE tubing with only the extruder motor pulling it up.
Another possibility is filament type: Was the Amazon filament bundle PLA? Is there any chance the filament is PETG or ABS or another type? The spools have the material type printed on them. If the material is NOT PLA then when you unload, select the correct material.
So get back with the printer model, and Amazon filament type; and if filament is still stuck - unloadable. We can focus on the jam after we figure out why it isn't unloading.
RE: Brand new printer. Clogged extruder. Help :[
In trying to clean the nozzle with a high nozzle temp, in addition to trying to poke it clear I've found manually feeding filament through also helped.
I had been printing PLA and it jammed up on me. One of the steps I took was to loosen the idler door (MK3, not sure how I'm supposed to do that with the MK3S+MMU2S...), ran the temp up to 280, removed the nozzle, and then I manually pushed a different color PLA through (from my Amazon sample pack as it happens). When I did that a blob of the PLA that jammed popped out (it was hot, but not soft like the PLA I fed through to clear the jam). Note that the different color was specifically so I could see if the prior filament came out (like it did).
In my case it was the Prusa (not Prusament) Silver that jammed. Amazon's and Inland's PLAs work great for me. Never did get that print to work with the Prusa filament, but the same gcode worked fine with Amazon filament.
RE: Brand new printer. Clogged extruder. Help :[
Another way to help clear a jam, like Gnat is saying, if it is a simple filament oddity, is to heat the nozzle to 275c, use the Settings/Move Axis/E and extrude 20 to 50 mm of filament. If the filament is stuck, I'll open the idler door and push the filament down the path, or if that isn't working pull the filament back out of the hot end, then deal with the nozzle jam.
But do not let the filament bake at 275 or 280: it will cook and thoroughly jam to the point of part replacement, and may even damage the stock thermistor.
RE: Brand new printer. Clogged extruder. Help :[
Thanks everyone for the detailed replies. I don't like the idea of surgery, but gotta learn this stuff eventually.
Both filaments are PLA. I tried the unload via the main menu with no luck, thats when it grinds. Loading doesn't do anything.
I just tried the settings/ extrude at 230 and nothing happened. I did have it at 290 briefly when trying to use the unload method, as I saw someone mentioned in a youtube video, so its possible that I made it worse? It was having the issue before I tried this obviously.
The one weird thing I noticed is there is a little give on the filament, I can move it up half an inch when trying to pull it out, and back in, but what ever mechanism is in there won't let go of it.
Time for surgery as Holmes suggested, or is it probably caked and have to inquire about a replacement? The best lessons are usually never free =\
RE: Brand new printer. Clogged extruder. Help :[
Before you go tearing too much apart, I suggest locating a 15cm/6in length of 1.5mm rod. Heat the nozzle up, open the extruder door and gently guide the rod down through the filament feed, past the (opened) extruder gears, into the PTFE tube down to the hotend. With any luck, a bit of filament broke off and you'll be able to push it down to where it'll either melt in the hotend, or you can create enough room to feed more filament in. I've got some incomplete notes and pics on the process here. If you can't find a suitable rod, the hex wrench that came with your printer can at least push down as far as the PTFE tube.
You might also try heating up and removing the nozzle, and pushing from below.
I experienced 2 major clogs and filament breaks before realizing I could use this instead of dismantling my entire extruder. It turned a multi-hour fix into a 15 minute diversion.
RE: Brand new printer. Clogged extruder. Help :[
Well your explanation is exactly what I was looking for. Thank you, Any suggestions on where to find a rod? Sounds like it might come in handy later.
I guess I was putting off cutting the filament since its a nice handle to try to pull out but sounds like i've exhausted all tries using the unload function?
RE: Brand new printer. Clogged extruder. Help :[
[...] Any suggestions on where to find a rod? Sounds like it might come in handy later.
I happened to have a length of stiff wire handy. An old-fashioned coat hanger wire might be suitable. Do polish the cut ends to avoid snagging the PTFE tubing. Good luck with it.
RE: Brand new printer. Clogged extruder. Help :[
If there is filament showing at the gears, the rod is not needed. Sometimes the chewing will cut the filament, so that nothing is showing above the PTFE tube - that is the situation Bob is referring to. Like this:
Instead, if you can see filament above the gear, try opening the door as shown, heat the nozzle to 275c, then use needle nose pliers to grab the filament and see if you can get upward movement.
If you can remove the filament, you're one step closer to doing what is called a "cold pull" cold pull to clear the nozzle.
RE: Brand new printer. Clogged extruder. Help :[
I just checked and Amazon has 1.5mm wire -- lots of it -- for hobbies. Unfortunately they don't mention how hard/soft it is.
RE: Brand new printer. Clogged extruder. Help :[
I think what you're suffering is a blob of melted filament in the heat break cool zone, and it isn't pulling back out through the PTFE.
If you heat the nozzle up to 280c, (bed can be cool); then use a wrench to hold the heater block, and a socket to remove the nozzle. Take care though, 280c is very hot and burns you before you feel it.
E3D-V6 Nozzle Exchange Procedure
Once the nozzle is out, you can try pushing the filament down through the heat break. If this doesn't free up the filament, then you'll need to remove the heat break from the heat sink.
And don't leave the heater on too long, you can toast the thermistor. And 280c is the limit; never exceed that temp or you WILL toast the thermistor.